Abstract

Growing three dimensional (3D) cells is an emerging research in tissue engineering. Biophysical properties of the 3D cells regulate the cells growth, drug diffusion dynamics and gene expressions. Scaffold based or scaffoldless techniques for 3D cell cultures are rarely being compared in terms of the physical features of the microtissues produced. The biophysical properties of the microtissues cultured using scaffold based microencapsulation by flicking and scaffoldless liquid crystal (LC) based techniques were characterized. Flicking technique produced high yield and highly reproducible microtissues of keratinocyte cell lines in alginate microcapsules at approximately 350 ± 12 pieces per culture. However, microtissues grown on the LC substrates yielded at lower quantity of 58 ± 21 pieces per culture. The sizes of the microtissues produced using alginate microcapsules and LC substrates were 250 ± 25 μm and 141 ± 70 μm, respectively. In both techniques, cells remodeled into microtissues via different growth phases and showed good integrity of cells in field-emission scanning microscopy (FE-SEM). Microencapsulation packed the cells in alginate scaffolds of polysaccharides with limited spaces for motility. Whereas, LC substrates allowed the cells to migrate and self-stacking into multilayered structures as revealed by the nuclei stainings. The cells cultured using both techniques were found viable based on the live and dead cell stainings. Stained histological sections showed that both techniques produced cell models that closely replicate the intrinsic physiological conditions. Alginate microcapsulation and LC based techniques produced microtissues containing similar bio-macromolecules but they did not alter the main absorption bands of microtissues as revealed by the Fourier transform infrared spectroscopy. Cell growth, structural organization, morphology and surface structures for 3D microtissues cultured using both techniques appeared to be different and might be suitable for different applications.

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Acknowledgements

The authors are grateful to the research financial support (Science Fund Vot No.: 0201-01-13-SF0104 or S024) awarded by Malaysia Ministry of Science and Technology (MOSTI) and IGSP Grant Vot No. U679 awarded by Universiti Tun Hussein Onn Malaysia. We acknowledge the help of Arina Basyirah Ismail for routine cell sub-culture.

Author’s contribution

CFS produced the conception of the paper and prepared the manuscript of the paper. KST designed and fabricated the flicker machine. SCW performed the microencapsulation of 3D cells and quantification of microtissues. CFS conducted the 3D cell culture and staining experiments of the microtissues. NN performed the FE-SEM imaging of the microtissues. MKA conducted the FTIR experiments and NS analyzed the FTIR results. FS helped to analyze and interpret the cells staining results. MY synthesized and prepared the liquid crystals. SA/LS prepared the samples for the histological sectioning.